From nlopez@cmu.edu Wed Jan 03 11:20:04 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!cmu!nlopez From: nlopez@cmu.edu (Nadia López) Newsgroups: comp.sys.m68k Subject: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Jan03.112004.3619@cmu.edu> Date: Wed, 03 Jan 1996 11:20:04 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 Lines: 10 Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. The board features two 68000 CPUs clocked at 12 MHz sharing a dual-ported 128KB static RAM bank. Disassembling ROM #0 reveals an initialization routine that checks for a hardware dongle marked 'ORION-ENC-84'. One 28-pin EPROM socket (labeled U14) is completely empty. What firmware was supposed to be in that socket? -- Nadia López Tape trading list upon request. SASE required for international mail. From dnilsson@demon.co.uk Fri Jan 05 05:33:04 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!demon!dnilsson From: dnilsson@demon.co.uk (Dong-hyun Nilsson) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Jan05.053304.6510@demon.co.uk> Date: Fri, 05 Jan 1996 05:33:04 GMT References: <1996Jan03.112004.3619@cmu.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jan03.112004.3619@cmu.edu>, nlopez@cmu.edu (Nadia López) writes: > Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. Tom from Ashford Poly owns the physical board! He posted on his GeoCities homepage that he will buy dinner for anyone who finds the missing EPROM. -- Dong-hyun Nilsson "Extraordinary claims require extraordinary spectra." PC-9821Ap2 (NEC) / Linux 1.2.13 From mkang@earthlink.net Fri Jan 05 22:13:04 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!mkang From: mkang@earthlink.net (Mateo Kang) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Jan05.221304.2306@earthlink.net> Date: Fri, 05 Jan 1996 22:13:04 GMT References: <1996Jan03.112004.3619@cmu.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Jan03.112004.3619@cmu.edu>, nlopez@cmu.edu (Nadia López) writes: > Managed to dump the 27256 EPROMs from the TWIN-68 Rev C board recovered from Ashford Poly. That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Mateo Kang -- EarthLink Network "We don't sign stars. We build them." From dtakahashi@uu.net Sat Jan 06 15:49:04 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!uu!dtakahashi From: dtakahashi@uu.net (Dmitri Takahashi) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Jan06.154904.6144@uu.net> Date: Sat, 06 Jan 1996 15:49:04 GMT References: <1996Jan03.112004.3619@cmu.edu> <1996Jan05.221304.2306@earthlink.net> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jan05.221304.2306@earthlink.net>, mkang@earthlink.net (Mateo Kang) writes: > That dual-ported SRAM design is ingenious. It avoids bus arbitration contention between the two 68k processors entirely. Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. -- === Dmitri Takahashi === Dept of Electrical Engineering, UUNET Technologies, Falls Church VA "They will send a copy in my place." From lkarlsson@unam.mx Sun Jan 07 03:24:04 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!unam!lkarlsson From: lkarlsson@unam.mx (Lars Karlsson) Newsgroups: comp.sys.m68k Subject: Re: TWIN-68 Rev C coprocessor board - schematic analysis & EPROM dump Message-ID: <1996Jan07.032404.1165@unam.mx> Date: Sun, 07 Jan 1996 03:24:04 GMT References: <1996Jan03.112004.3619@cmu.edu> <1996Jan05.221304.2306@earthlink.net> <1996Jan06.154904.6144@uu.net> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Jan06.154904.6144@uu.net>, dtakahashi@uu.net (Dmitri Takahashi) writes: > Socket U14 was probably for the decryption key lookup table. Without that EPROM, CPU #1 is running in an idle loop. Marcus Hale designed the TWIN-68 board before he disappeared. That's why his initials are on the PCB silkscreen. -- Lars Karlsson "They will send a copy in my place." Acorn RiscPC 600 / SunOS 4.1.4